Meter electronics and methods for verification diagnostics for a flow meter

Abstract

Meter electronics ( 20 ) for a flow meter ( 5 ) is provided according to an embodiment of the invention. The meter electronics ( 20 ) includes an interface ( 201 ) for receiving a vibrational response from the flow meter ( 5 ) and a processing system ( 203 ) in communication with the interface ( 201 ). The vibrational response is a response to a vibration of the flow meter ( 5 ) at a substantially resonant frequency. The processing system ( 203 ) is configured to receive the vibrational response from the interface ( 201 ), determine a frequency (ω 0 ) of the vibrational response, determine a response voltage (V) and a drive current (I) of the vibrational response, measure a decay characteristic (ζ) of the flow meter ( 5 ), and determine the stiffness parameter (K) from the frequency (ω 0 ), the response voltage (V), the drive current (I), and the decay characteristic (ζ).

We claim: 
     
       1. Meter electronics ( 20 ) for a flow meter ( 5 ), the meter electronics ( 20 ) comprising:
 an interface ( 201 ) for receiving a vibrational response from the flow meter ( 5 ), with the vibrational response comprising a response to a vibration of the flow meter ( 5 ) at a substantially resonant frequency, and a processing system ( 203 ) in communication with the interface ( 201 ), the meter electronics ( 20 ) further comprising: 
 the processing system ( 203 ) being configured to receive the vibrational response from the interface ( 201 ), determine a frequency (ω 0 ) of the vibrational response, determine a response voltage (V) and a drive current (I) of the vibrational response, measure a decay characteristic (ξ) of the flow meter ( 5 ), and determine a stiffness parameter (K) of the flow meter from the frequency (ω 0 ), the response voltage (V), the drive current (I), and the decay characteristic (ξ). 
 
     
     
       2. The meter electronics ( 20 ) of  claim 1 , with the measuring the decay characteristic (ζ) further comprising allowing the vibrational response of the flow meter ( 5 ) to decay down to a predetermined vibrational target. 
     
     
       3. The meter electronics ( 20 ) of  claim 1 , with the processing system ( 203 ) being further configured to measure the decay characteristic (ζ) by removing excitation of the flow meter ( 5 ) and allowing the vibrational response of the flow meter ( 5 ) to decay down to a predetermined vibrational target while measuring the decay characteristic. 
     
     
       4. The meter electronics ( 20 ) of  claim 1 , with the stiffness parameter (K) comprising K=(I*BL PO *BL DR *ω 0 ) /2ζV. 
     
     
       5. A method for determining a stiffness parameter (K) of a flow meter, the method comprising:
 receiving a vibrational response from the flow meter, with the vibrational response comprising a response to a vibration of the flow meter at a substantially resonant frequency, and determining a frequency (ω 0 ) of the vibrational response, the method further comprising: 
 determining a response voltage (V) and a drive current (I) of the vibrational response; 
 measuring a decay characteristic (ξ) of the flow meter; and 
 determining the stiffness parameter (K) from the frequency (ω 0 ), the response voltage (V), the drive current (I), and the decay characteristic (ξ). 
 
     
     
       6. The method of  claim 5 , with the measuring the decay characteristic (ζ) further comprising allowing the vibrational response of the flow meter to decay down to a predetermined vibrational target. 
     
     
       7. The method of  claim 5 , with the measuring the decay characteristic (ζ)further comprising:
 removing excitation of the flow meter; and 
 allowing the vibrational response of the flow meter to decay down to a predetermined vibrational target while measuring the decay characteristic. 
 
     
     
       8. The method of  claim 5 , with the stiffness parameter (K) comprising K=(I*BL PO *BL DR *ω 0 ) /2ζV. 
     
     
       9. A method for determining a stiffness change (ΔK) in a flow meter, the method comprising:
 receiving a vibrational response from the flow meter, with the vibrational response comprising a response to a vibration of the flow meter at a substantially resonant frequency, and determining a frequency (ω 0 ) of the vibrational response, the method further comprising: 
 determining a response voltage (V) and a drive current (I) of the vibrational response; 
 measuring a decay characteristic (ξ) of the flow meter; 
 determining a stiffness parameter (K) of the flow meter from the frequency (ω 0 ), the response voltage (V), the drive current (I), and the decay characteristic (ξ); 
 receiving a second vibrational response from the flow meter at a second time t 2 ; 
 generating a second stiffness characteristic (K 2 ) of the flow meter from the second vibrational response; 
 comparing the second stiffness characteristic (K 2 ) to the stiffness parameter (K); and 
 detecting the stiffness change (ΔK) if the second stiffness characteristic (K 2 ) differs from the stiffness parameter (K) by more than a predetermined tolerance. 
 
     
     
       10. The method of  claim 9 , further comprising detecting the stiffness change (ΔK) if the second stiffness characteristic (K 2 ) differs from the stiffness parameter (K) by more than a predetermined stiffness tolerance. 
     
     
       11. The method of  claim 9 , further comprising quantifying the stiffness change (ΔK) from the comparing. 
     
     
       12. The method of  claim 9 , with the measuring the decay characteristic (ζ) further comprising allowing the vibrational response of the flow meter to decay down to a predetermined vibrational target. 
     
     
       13. The method of  claim 9 , with the measuring the decay characteristic (ζ) further comprising:
 removing excitation of the flow meter; and 
 allowing the vibrational response of the flow meter to decay down to a predetermined vibrational target while measuring the decay characteristic. 
 
     
     
       14. The method of  claim 9 , with the stiffness parameter (K) comprising K =(I*BL PO *BL DR *ω 0 ) /2ζV. 
     
     
       15. The method of  claim 9 , with the generating the second stiffness characteristic (K 2 ) from the second vibrational response comprising generating the second stiffness characteristic (K 2 ) from a second frequency, a second response voltage, a second drive current, and a second damping characteristic.